class I18n(object):
    """
    国际化
    Attributes:
        _zh:中文
        _en:英文
    """
    _zh = {
        "login_fail": "登录失败"
    }
    _en = {
        "login_fail": "login fail"
    }

    @classmethod
    def lang(cls, msg, lang="zh"):
        if lang == "zh":
            return cls._zh[msg]
        return cls._en[msg]
